Peptidyl Prolyl cis trans Isomerase A is a mouthful, but it has a very specific spelling. The first three words use standard English spelling rules, but the last five words are more complex. "Cis" and "trans" refer to the spatial orientation of molecules, while "prolyl" and "peptidyl" indicate the type of amino acid involved. "Isomerase" denotes an enzyme that catalyzes the conversion of one isomer to another. The final "A" indicates a specific subtype of this enzyme. Transcribed in IPA as /ˈpɛptɪdəl ˈproʊlɪl sɪs træns aɪsoʊˈmɛrəs ˌeɪ/ it makes the spelling clearer.
Peptidyl Prolyl cis trans Isomerase A (PPIA) is an enzyme that belongs to the family of peptidyl-prolyl cis-trans isomerases (PPIases). PPIases are a group of enzymes that catalyze the cis-trans isomerization of peptide bonds involving proline residues in proteins. PPIA, also known as cyclophilin A, is one of the most extensively studied members of this enzyme family.
PPIA plays a critical role in protein folding, stability, and function. It helps in the correct folding of newly synthesized proteins and promotes their stability by catalyzing the rotation of the peptide bond between proline residues from the cis to the trans conformation or vice versa. As proline residues are commonly found in polypeptide chains and are known to introduce structural constraints, the isomerization of their peptide bonds is often necessary to allow proper protein folding and conformational changes.
Beyond its role in protein folding, PPIA has been implicated in various cellular processes, including signal transduction, immune responses, and cell proliferation. It has also been associated with the pathogenesis of certain diseases, such as cancer, viral infections, neurodegenerative disorders, and autoimmune diseases.
Inhibition of PPIA activity has emerged as a potential therapeutic strategy in the treatment of diseases where its dysregulation is implicated. Therefore, PPIA inhibitors have been actively studied as potential drug candidates that could modulate protein function and potentially halt disease progression.